The PHT-771 Digital Psychrometer simultaneously displays %RH, temperature as well as dew point, web bulb or probe temperature. It calculates the T1-T2 differential with the Thermistor Temperature Probe (sold separately). The handheld PHT-771 hygro-thermometer psychrometer, weighing only 3.3 oz. (95g), has a basic accuracy of 0 to 100%RH (±3%RH) for humidity and ±1.8°F (±1°C) for internal and external temperature.

Other features of the PHT-771 hygro-thermometer include data hold, auto power off, and MAX / MIN readings. This psychrometer can also calculate the T1-T2 differential using the optional probe and T2-Dew Point.

The PHT-771 hygro-thermometer psychrometer comes ready to operate with two AAA batteries. Simply twist sensor cap for protection in storage.